1. Field of the Invention
This invention is directed to an intake for rotary drums for thermal treatment of material such as tube radiators, rotary tubular kilns, and the like, consisting of a stationary or movable housing surrounding an intake opening of the rotary drum, together with a chute which is a provided with a refractory lining and arranged to direct the material to the intake opening of the rotary drum.
2. Description of the Prior Art
Product intake chutes, for example, at cooling drums which follow a cement clinker calciner are subject to a high, mechanically abrasive thermal load which may result in a progressive erosion of the lining, particularly in the area of the discharge end. This wear is partially produced by the impact of falling pieces of large cement clinker which leave the calciner and proceed into the cooling drum. When the thickness of the refractory lining falls below a minimum dimension, permanent deformations of the outer jacket can occur due to excessive thermal stresses so that replacement of the chute becomes necessary.
There has been a suggestion to protect the discharge area of rotary tubular kilns, for example, by providing air cooled protector segments disposed on brackets, the segments directly following the end of the kiln jacket and thus forming a discharge ring. The protector segments not only prevent an overload at the actual end of the kiln jacket but also simultaneously form an absorpotion point for the axial thrust developed by the rotary tubular kiln lining. This is accomplished by means of inwardly directed cams which are disposed thereon. Such embodiments of a rotary tubular kiln discharge are shown, for example, in the reference "Zement-Kalk-Gips" No. 2, 1975, p. 57.
It has also been suggested to support a stationarily disposed intake chute of a rotary tubular kiln which is covered with a refractory lining and is preceded by a cyclone heat exchanger by means of refractory retaining rings which are disposed at right angles to the flow direction of the material. Webs are welded to the metallic surface of the chute and proceed in the same direction as the refractory retaining rings at certain intervals, and likewise serve to anchor the lining.